The Obesity Society (TOS) has updated its 2008 position statement on obesity and has classified obesity as a worldwide, non-communicable chronic disease. The new report, ‘Obesity as a Disease: The Obesity Society 2018 Position Statement’, published in the January 2019 issue of Obesity, notes that obesity is a multi-causal chronic disease recognised across the lifespan resulting from long-term, positive, energy imbalance with development of excess adiposity that over time leads to structural abnormalities, physiological derangements, and functional impairments. The disease of obesity increases the risk of developing other chronic diseases, including but not limited to diabetes, hypertension, cancer and cardiovascular disease, and is associated with an increased risk for premature mortality.

"The science of obesity has advanced over the past decade, leading TOS to affirm, update and strengthen its position on obesity as a disease that afflicts all age groups," said TOS President, Dr Steven B Heymsfield, professor and director of the Metabolism and Body Composition Laboratory at the Pennington Biomedical Research Center in Baton Rouge, LA. Heymsfield and TOS Vice President, Dr Cathy Kotz, both noted that multiple health societies and organisations have recognised obesity as a disease since the initial TOS position statement. Kotz, however, added that a large degree of misconception remains.

TOS ascribes to the position that the benefits of defining obesity as a disease outweigh the commonly advanced counterarguments. For instance, that excess adiposity should be viewed as an intermediate risk factor rather than as a disease per se or that medicalising obesity would increase rather than decrease some of the adverse social and psychological consequences for those afflicted, according to the report.

"Obesity meets all criteria for being a disease, and therefore, should be characterized as such," said Kotz, professor and director of graduate studies at the University of Minnesota's Department of Integrative Biology and Physiology in Minneapolis. "This recognition impacts how individuals are viewed and should reduce the stigma associated with it. The statement is needed so that the public and policymakers can make informed decisions regarding the healthcare surrounding obesity."

The authors state the importance of moving beyond a debate centring on whether obesity is a chronic disease to advance the dialogue toward identifying and implementing solutions. TOS has outlined 13 objectives, including recognizing the need for research funding, reducing stigma and discrimination, educating healthcare providers, and promoting the need for increased obesity prevention and treatments, in addition to structural and environmental changes in workplaces, schools and communities.

"One important feature of this updated statement from TOS is the position that obesity, even in childhood, is a disease,” said Dr Aaron Kelly, past chair of the TOS Pediatric Obesity Section and co-director of the University of Minnesota Center for Pediatric Obesity Medicine. “Too often paediatric obesity is chalked up to ineffective parenting and/or lack of willpower on the part of the child. In fact, when obesity surfaces in childhood, it may reflect a particularly aggressive form of the disease likely driven by a strong biological component. Therefore, paediatric obesity should be taken seriously by all stakeholders.”

"Recognising obesity as a disease neither discounts the role of the individual to manage their health nor does it take the onus off of policymakers to promote healthful food and physical activity environments,” concluded Society Councilor for Advocacy/Public Affairs/Regulatory Scott Kahan of Johns Hopkins Bloomberg School of Public Health in Baltimore, MD. “Most simply, this designation implies that as a society, we should take obesity as seriously as other behaviour-related diseases that affect our collective health.”